1. Field of the Invention
This invention pertains to a modular digital signal cross-connect (DSX) assembly. More particularly, this invention pertains to a modular DSX assembly for high speed transmission signals carried over coaxial cables. This invention also pertains to DSX assemblies with switching monitor jacks.
2. Background of the Prior Art
Digital signal cross-connect systems (DSX) provide a location for interconnecting two digital transmission paths. The apparatus for a DSX is located in one or more frames, or bays, usually in a telephone central office. The DSX apparatus also provides jack access to the transmission path.
DSX jacks are well-known. A modular DSX jack assembly is described and claimed in commonly assigned U.S. Pat. No. 4,840,568.
DSX equipment for use with high speed signals (such as telecommunication industry standards DS-3 and DS-4 transmission rates) include coaxial cables for carrying the signals. An example of such is described in U.S. Pat. No. 4,815,104, which includes switching coax jacks.
The circuitry of a different prior art coax DSX jack is shown in FIG. 2 of the aforesaid U.S. Pat. No. 4,815,104. As indicated, the circuitry includes a plurality of jacks (including signal-in and signal-out jacks) joined with connectors (e.g., equipment-in and equipment-out connectors) by coax cables. The circuitry also includes cross-connect points which may be forward facing jacks or rear facing connectors. One or more monitor jacks permit monitoring of a signal at preselected points in the circuit.
Prior art coax DSX jacks are semi-modular in that the cross-connect circuitry, jacks and related coax connectors for each circuit are housed in a unique jack frame such as that shown in FIG. 1 of the aforesaid U.S. Pat. No. 4,815,104. However, the modularity of the design is hampered in that such prior art jack assemblies are not easily mounted or dismounted from a prewired installation. Therefore, they do not enjoy the full benefits of the modularity of design of the aforesaid commonly assigned U.S. Pat. No. 4,840,568. Also, present coax DSX designs do not permit the addition of circuit enhancements (such as repeater circuits) to the DSX module. Such a function is a benefit described in the aforementioned U.S. Pat. No. 4,840,568.
It is an object of the present invention to provide a coax DSX module with enhanced modularity and which is adaptable to receive circuit enhancements. It is also an object of the present invention to provide a DSX jack with a monitor which can be switched to monitor any one of a plurality of signal paths in the DSX assembly.